As disclosed in the international patent application PCT/EP2015/001454, filed on 15 Jul. 2015 by the same applicants, which is incorporated herein by reference, facade units may be used to provide for a specific visual perception of an outdoor wall of a building for an observer. In particular, those facade units may provide specific chromatic and reflective features that provide for properties of sun imitating reflection such as described, for example, in WO 2015/172821 A1 by the same applicants.
For example, in modern architecture, facade structures combine a large variety of functions. Primarily, there is the aesthetic aspect addressing the perception of a building and how it is perceived in the environment of other buildings, under different weather conditions, and respective illumination situations. Furthermore, active illumination of buildings allows providing specific visual impressions of buildings even at night.
On Rayleigh-like diffusing layers, several applications such as EP 2 30 478 A1, EP 2 304 480 A1. WO 2014/076656 A1, and WO 2015/172821 A1 filed by the same applicants, disclose lighting systems that use a light source producing visible light, and a panel containing nanoparticles used in transmission or reflection. During operation of those lighting systems, the panel receives the light from the light source and acts as a so-called Rayleigh diffuser, namely it diffuses incident light similarly to the earth atmosphere in clear-sky conditions. Specifically, the concepts refer to directional light with lower correlated color temperature (CCT), which corresponds to sunlight, and diffuse light with larger CCT, which corresponds to the light of the blue sky.
Introducing a reflective chromatic feature in a facade of a building as proposed, for example, in the international patent application PCT/EP2015/001454 mentioned above will redirect sun light towards the ground at the bottom of the building.
Thus, the present disclosure is directed, at least in part, to improving or overcoming one or more aspects of prior systems.